The reality of reselling in 2026 is simple: more marketplaces mean more sales. Buyers are spread across different shopping apps like eBay, Poshmark, Etsy, and Mercari. If you list an item in only one place, you limit who can see it.
Manual cross-posting—copying and pasting every detail—kills your growth. It takes too much time and leads to many mistakes. This is why cross listing tools have become the industry standard.
Sidekick Tools is one of the more comprehensive cross listing apps available today. This blog will show you how it works and if it is right for your reselling needs. We will look at its features, pricing, and how it stacks up against the competition.
So, let’s begin!
What is a Cross Listing App?
A cross listing app is a tool that lets you post one item to many marketplaces at the same time. Instead of doing the work five times, you do it once. It connects your marketplace accounts so you can manage everything from one app.
1.Saves Time by Listing Once, Posting Everywhere
Instead of manually entering product details on each marketplace, a cross listing tool lets you:
- Write your title once.
- Upload photos once.
- Sync listings details and prices across all platforms.
This cuts hours of work for every item you sell. When you save time on the small stuff, you can focus on finding more items to resell.
2.Keeps Inventory Consistent
Good cross listing tools help you stay organized. They automatically sync your quantity and update the status when an item sells. This helps you avoid:
- Overselling: Selling an item you no longer have.
- Confusion: Forgetting to delete a sold item from a different app.
3.Boosts Exposure & Sales Opportunities
More marketplaces equal more buyers. Cross listing tools put your items where people shop, which increases your views and offers. Different buyers hang out on different shopping apps, so being everywhere increases your chances of a fast sale.
4.Simplifies Price & Management
You can change your price once and push that update to all marketplaces. If you want to run a sale or discount, you can do it across all marketplaces at once. This keeps your pricing strategy smooth and professional.
5.Reduces Errors & Improves Accuracy
Manual listing of items leads to typos and missing details. With a cross listing tool, your listings stay uniform and your branding looks professional. This builds trust with buyers and helps you rank higher in search results.
6.Makes Bulk Actions Easy
With a cross listing tool, you can cross post dozens of items in a single batch. You can also edit multiple listings or relist old items quickly. High efficiency leads to higher revenue.
What is Sidekick Tools?
Sidekick Tools started as “Posh Sidekick,” a tool just for Poshmark. Today, it is a full automation app designed to handle the “boring stuff” of reselling. It is built for serious marketplace resellers who want to scale.
The app supports the most popular platforms:
- eBay
- Poshmark
- Mercari
- Depop
- Etsy
- WhatNot
- Grailed
Sidekick Tools positions itself not just as a cross listing app but also as a marketplace automation app with powerful AI automation tools like relisting, auto-delisting, sharing, offer to likers/buyers, etc. It is an all-in-one app for managing your entire reselling business.
Core Cross Listing Features of Sidekick Tools
Sidekick Tools makes it easy to move your inventory across the internet. It is built to be fast and reliable for high-volume sellers.
1.One-Click Cross Listing
You can cross post your listings between marketplaces with one click. The Sidekick Tools app syncs your title, description, photos, price, and SKU. It ensures that the right data goes to the right place.
2.Bulk Cross Listing
If you have hundreds or thousands of items, you cannot do them one by one. Sidekick Tools allows you to bulk cross post items. This is perfect for power resellers who need to move large amounts of inventory fast.
3.Smart Listing Customization
Every marketplace is a little bit different. Sidekick lets you tweak your titles or prices for a specific marketplace. This helps you optimize each listing for the specific audience on that shopping app.
4.Inventory Protection
The app helps prevent “double-selling” by monitoring your inventory. It uses automatic delisting to remove items as soon as they sell. This protects your seller rating and keeps your buyers happy.
Automation + Cross Listing: The Sidekick Tools Advantage
Cross listing alone is no longer enough to win in 2026. You also need to stay active on every marketplace. Sidekick Tools stands out because it includes built-in automation features.
The app handles tasks such as:
- Auto Delisting: Removes sold items instantly.
- Auto Relisting: Refreshes old listings to the top of search results.
- Auto Offers: Sends discounts to buyers who “like” your items.
- Poshmark Sharing: Shares your Posh closet 24/7 to boost visibility.
These features help you rank higher in marketplace algorithms. When the Sidekick Tools app does the work, your marketplace listings stay fresh and visible without you touching your phone.
AI Tools Inside Sidekick Tools
Sidekick Tools integrated several AI-powered tools to give marketplace resellers a competitive edge. These AI tools help your listings look better and rank higher than basic listings.
The AI tools include:
- AI Listing Content Generator: Generates SEO-optimized titles and descriptions for listings.
- AI Stock Photo Creator: Turns basic photos into professional studio shots.
- Background Remover: Quickly cleans up messy backgrounds from product images.
Using AI tools for listing optimization helps you beat competitors who are still doing everything by hand. Professional photos and SEO-friendly listing content lead to higher conversion rates.
Ease of Use: Is Sidekick Tools Beginner-Friendly?
Using the Sidekick Tools app is straightforward. The dashboard is designed to be clean and easy to navigate. New users will find it easy to link their marketplace accounts and start cross listing within minutes.
While most marketplace cross listing tools feel like “technical” software, Sidekick Tools is a great mobile app with amazing UI and features. The learning curve is small, making it a great choice for both new and experienced resellers.
Supported Marketplaces & Future Expansion
Sidekick currently supports the “Big 7” marketplaces for resellers, including Poshmark, eBay, Mercari, Etsy, WhatNot, Grailed, and Depop.
The Sidekick Tools’ development team is constantly adding new features to the app. Recent updates include “Offers to Likers” for Depop and “Follow” features for WhatNot. This ongoing development means the app grows as your business grows.
Sidekick Tools Pricing
Sidekick Tools offers several cross listing packages based on how many items you need to cross-post each month. Here are the details:
| Cross Listing Plan | Price | Monthly Cross-Posts |
| Basic | $9.99 | 100 items |
| Silver | $19.99 | 250 items |
| Gold | $29.99 | 500 items |
| Pro | $39.99 | 750 items |
| Enterprise | $44.99 | 1000 items |
For most resellers, the time saved pays for the Sidekick Tools’ cross listing subscription in the first week. The best ROI comes from the “Pro” and “Enterprise” plans, which include the advanced AI and automation tools.
Sidekick Tools vs Other Crosslisting Tools
| SIDEKICK TOOLS |
VENDOO | CROSSLIST | PRIME LISTER |
RESELL KIT | SELLER AIDER |
FLYP | |
| Number of Supported Marketplace | 7 | 11 | 9 | 8 | 6 | 5 | 6 |
| iOS & Android App | YES | YES | NO | YES | NO | NO | NO |
| Web App | YES | YES | YES | YES | NO | NO | YES |
| Pricing | Starts at $9.99/month | Starts at $29.99/month | Starts at $29.99/month | Starts at $49.99/month | Starts at $9.30/month | Starts at $12/month | Starts at $9/month |
| Free Trial | YES | YES | NO | NO | NO | YES | YES |
| Inventory Management | YES | YES | YES | YES | YES | NO | NO |
| Auto Delist | YES | YES | YES | NO | YES | YES | YES |
| Relist | YES | YES | YES | YES | YES | YES | YES |
| Auto Posh Auction |
YES | NO | NO | NO | NO | NO | NO |
| Offer to Liker/Buyer | YES | YES | NO | YES | NO | YES | YES |
| Posh Sharing | YES | YES | NO | YES | NO | YES | YES |
| Bulk Listing Editing | YES | YES | NO | YES | NO | NO | NO |
| AI Product Description Generator | YES | NO | NO | NO | NO | NO | NO |
| Stock Photo Creator | YES | NO | NO | NO | NO | NO | NO |
| AI Image BG Remove | YES | YES | YES | NO | NO | NO | YES |
| Sales Analytics & Reports | YES | YES | NO | NO | NO | NO | YES |
| Community Support | YES | YES | NO | NO | NO | NO | YES |
Sidekick Tools Pros and Cons
Pros:
- All-in-one automation and cross listing app.
- Powerful AI tools for photo editing and product description writing.
- Works across 7 major marketplaces (more coming).
- Cloud-based (no Chrome extension needed).
Cons:
- Might be too much for very small resellers (under 50 items).
- Higher costs for advanced automation features.
Is Sidekick Tools Really the Best Cross Listing App?
Sidekick Tools is arguably one of the popular cross listing apps among resellers because it brings three things in one app: cross listing feature, automation tools for marketplaces, and AI tools for listing optimization.
Most cross-posting apps only help you copy a listing from one marketplace to another. Sidekick Tools goes further by helping you manage your listings after they are posted, which saves you hours of manual labor every week.
By handling the repetitive “grind” of reselling, the Sidekick Tools app solves the biggest problem for most online resellers: a lack of time. It automatically relists your items and sends offers to interested buyers while you sleep.
Beyond cross listing and marketplace automation, Sidekick Tools uses smart technology to protect your reputation. When an item sells on one marketplace, the app immediately removes it from all others. This prevents the mistake of selling the same item twice.
Because the Sidekick Tools app handles these technical details, it serves more like a human VA rather than just a basic reseller automation tool. Moreover, it has AI tools to write product descriptions and create stunning product images. These tools help your listings look better and sell faster without extra effort on your part.
