Comparison

Joint Active Systems vs Quell Flex

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head

About

Joint Active Systems

Features

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The Joint Active Systems mobile app includes tools to help with the use of your JAS device. JAS devices safely restore joint motion using stress relaxation and low-load stretch: the very technique therapists use when providing hands-on therapy in the clinic.

About

Quell Flex

Features

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After pairing their Quell Flex devices to the Quell Flex app, users can: - Start and stop therapy - Control stimulation intensity - Check therapy status (e.g., time left in session) - Check device battery level - Review informational videos and other materials related to the devices * You should consult your physician before making changes to your chronic pain treatment plan.

Screenshots

Joint Active Systems3 screens

Quell Flex4 screens

Verdict

The call

The clearest difference is iOS requirement: Joint Active Systems at 12.4 against Quell Flex's 16.6. On price, update cadence, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Joint Active Systems ships an update every 33 months, Quell Flex every 35 months. The most recent releases landed on January 1, 2026 and September 27, 2026 respectively.

Scorecard1 real difference · 5 level

Joint Active Systems versus Quell Flex: the parameters behind the verdict, then further details
Parameter	Joint Active Systems	Quell Flex
Price	Free	Free
Update frequency	Every 33 months — better	Every 35 months
Ads	No	No
In-app purchases	No	No
Devices	iPhone, iPod — better	iPhone
Requires iOS	12.4 — better	16.6
Further details — not scored
Size	2 MB	23 MB
Age rating	4+	12+
Developer	Bonutti Technologies	NeuroMetrix, Inc.

In-app purchases

None

Joint Active Systems

No in-app purchases

None

Quell Flex

No in-app purchases

Questions

Is Joint Active Systems free?

Joint Active Systems is free to download, with no in-app purchases.

Is Quell Flex free?

Quell Flex is free to download, with no in-app purchases.

Do Joint Active Systems or Quell Flex have ads?

Neither Joint Active Systems nor Quell Flex shows ads.

Which is updated more often, Joint Active Systems or Quell Flex?

Joint Active Systems ships an update every 33 months, and Quell Flex every 35 months. Most recently, Joint Active Systems was updated on January 1, 2026 and Quell Flex on September 27, 2026.