MixMaxerFast Bundle, Kaching Bundles and Pumper are the three most-reviewed bundle apps on the Shopify App Store, each with thousands of five-star reviews and the Built for Shopify badge. They are good products. This page is for merchants who like the product and dislike the invoice, which, if you read their one-star reviews, is a specific and recurring group.
We make a competing app. The comparison below sticks to what is on each vendor's public pricing page and in public reviews as of 28 October 2026. Prices change; check the listing before you decide.
The pricing model, in one table
| App | Model | Lowest paid plan | What moves the price up | Highest listed plan |
|---|---|---|---|---|
| Fast Bundle | Tiers by monthly bundle revenue, plus feature gating | $19/mo | Bundle revenue crossing a tier (the jump from the $49 tier to the $139 tier happens around $3,000 of bundle sales) | $139/mo on the App Store; an Enterprise tier at $299/mo on fastbundle.co |
| Kaching Bundles | Tiers by "additional revenue" | $14.99/mo | Attributed revenue crossing a tier ($59.99 at about $10,000) | $59.99/mo on the App Store; higher tiers up to $299/mo on kachingappz.com |
| Pumper | Tiers by "additional revenue" | $9.99/mo | Attributed revenue; the free plan stops at about $300 | $49.99/mo (unlimited) |
| MixMaxer | Flat monthly fee | $9.99/mo | Nothing. No plan is capped by orders or revenue | $19.99/mo |
Two things to notice. First, "additional revenue" is defined by the app, and several reviews say the count includes whole orders, not only the bundle uplift. Second, the tier is crossed during your best weeks. A Black Friday that doubles bundle sales can move you two tiers for the month in which you least want to think about it.
What the one-star reviews actually say
We read the one- to three-star reviews of all three apps in October 2026. The complaints, in order of frequency:
- The price went up without a clear warning. "Started at $59.99, now $300." "They count the full order value, not the bundle."
- The free plan was not usable on a live store (Fast Bundle, Kaching: dev stores only, or revenue-capped).
- A discount bug that cost real money: a discount applied twice on a large order, a disabled offer still applying, the wrong variant on dozens of orders, a Black Friday outage.
- Aggressive follow-up after a negative review or an uninstall.
- Theme or page-builder conflicts (GemPages comes up for two of the three).
Complaints 1 and 2 are about the pricing model. Complaint 3 is about architecture: an app that computes prices in the theme and re-applies them at checkout will eventually disagree with itself.
Where the three apps are stronger
Fairness matters, because you will see these strengths in the five-star reviews and they are real:
- Support speed. All three run 24/7 chat and most positive reviews name a support agent by first name. If you want someone to write custom CSS for your theme at midnight, they will.
- Widget variety. Fast Bundle has the broadest catalogue of layouts; Kaching has polished "swatch" quantity selectors; Pumper bundles subscriptions in the same widget.
- Track record. Thousands of stores, years of edge cases found and fixed.
- Integrations lists. Long "works with" lists for cart drawers and page builders.
If your store does $50,000 a month in bundle revenue and you want a design agency on chat, the $299 tier may be fine. This page is for everyone below that.
What to ask any alternative before you switch
- Is the price tied to my revenue in any way, including a cap on the free plan? Ask for the sentence on the pricing page.
- Are discounts applied by a Shopify Function? This is what makes checkout, Shop Pay and POS charge the number the product page showed.
- What happens when two offers touch one item? You want a priority order, a "skip items already on sale" switch, and an overlap warning before publishing.
- Can I see what checkout will charge before I go live? A sample-cart test is worth more than a demo video.
- How does the dashboard count "revenue from the app"? If every order that contains a bundle counts, the number is flattering. Ask for an A/B test or a holdout group.
- What does uninstalling leave behind? Apps that edit theme.liquid leave code; app blocks and embeds do not.
MixMaxer as a flat-price alternative
- Pricing: Free (2 live offers, 1 running A/B test), Growth $9.99/month (unlimited offers, 3 tests), Pro $19.99/month (unlimited tests, holdout group, CSV export, weekly report). No per-order fee, no percentage of sales, no revenue cap on any plan. 30-day trial on paid plans.
- Offer types: volume tiers, fixed bundles, Buy X get Y, frequently bought together (learned from your orders), mix & match, post-purchase upsell.
- Architecture: every discount is a Shopify Function; the bundle is a real catalog product with per-component inventory; nothing is written into theme.liquid; discounts keep working if MixMaxer's servers are down.
- Price safety: offer priority decides which offer prices an item; two prices never stack; "skip items already on sale"; a "test at checkout" step runs the real discount on a sample cart before you publish.
- Proof: one-click A/B tests with profit per variant and an automatic winner at the confidence level you set; holdout group on Pro.
- Languages: every widget phrase per language, automatic RTL, admin in English or Arabic.
Where the three incumbents are ahead of MixMaxer today: live 24/7 chat (MixMaxer answers support email around the clock with an AI assistant and a human within about two hours on weekdays), the length of the "works with" list, and the number of widget layouts. Fixed bundles cannot be A/B tested yet.
Switching without breaking prices
- Build your offers in MixMaxer while the old app is still live, but publish them in an unpublished duplicate theme. Never run two bundle apps on a live theme; that is how double discounts happen.
- Use the "test at checkout" step with your three most common carts.
- Pause the old app's offers, publish the theme, re-run the same carts.
- Uninstall the old app last, then check the theme for leftover code.
FAQ
Does Fast Bundle charge based on revenue?
Yes. Fast Bundle's paid plans are tiered by monthly bundle revenue, with feature gating on top; as of October 2026 the App Store lists $19, $49 and $139 a month, with an Enterprise tier at $299 on the vendor site.
Does Kaching Bundles have a revenue limit?
Yes. Kaching's plans are tiered by attributed "additional revenue": $14.99, $29.99 and $59.99 on the App Store, with higher tiers on the vendor site. Reviews report moving up tiers during sales.
Is there a Shopify bundle app with no revenue cap?
MixMaxer charges a flat monthly fee (Free, $9.99, $19.99) with no cap on orders or revenue on any plan, including Free.
Can I run two bundle apps at once while switching?
Only in an unpublished duplicate theme. On a live theme two apps pricing the same product is the most common cause of double discounts.
Prices and review observations were checked on 28 October 2026 and will be rechecked every 60 days. MixMaxer on the Shopify App Store: apps.shopify.com/mixmaxer.