Comparison

COSS vs Dev Mastery

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

Head to head
About

COSS

Showcase your professional skills and earn digital badges to impress recruiters. Measure and certify your abilities in soft, technical, and mad skills to build a dynamic portfolio for job applications.

Highlights
  • Skill measurement and certification
  • Network-based feedback collection
  • Digital badges for soft and technical skills
  • CV and LinkedIn profile integration
  • Dynamic skills portfolio creation
  • 35+ soft skills, 200+ technical skills, 20 mad skills
Features
Read full description

Unlock Your Dream Opportunities with COSS! Ready to land that perfect internship, apprenticeship, or dream job? Look no further than COSS – the ultimate tool to showcase your talents and impress recruiters. With COSS, you can measure and certify your skills, just like the TOEIC test, but developed to assess your professional skills. Here's how it works: 1. Choose the skills you want to showcase. 2. Seek quick and simple feedback from your network – fellow students, professors, and professionals you work(ed) with during internships, apprenticeships or student jobs. 3. Discover your strengths and areas for growth with detailed results and expert recommendations. But that's not all! COSS takes your achievements to the next level. Earn digital COSS badges for your soft skills and display badges with your school's logo for your technical skills. Publish these badges on your CV and LinkedIn profile to make a lasting impression on potential employers. With COSS, you can build a dynamic skills portfolio for each job application. You have a full array of options: • 35 soft skills, including Adaptability, Effective Communication, and more. • 200 technical skills, from UX design to Financial Analysis and beyond. • 20 mad skills, covering everything from team leadership to music talents and volunteer experience. Don't miss out on the opportunity to boost your career. Download COSS now and stand out in the competitive job market. Your dream opportunity is just a click away!

About

Dev Mastery

Features
Read full description

Dev Mastery t'accompagne pour maîtriser SwiftUI et les bases de Swift. Parcours structurés (Débutant → Expert), leçons avec exemples de code, quiz pour valider chaque leçon, et défis pour mettre en pratique. Gagne des XP, suis ta progression et ton streak, consulte l’aide-mémoire Swift/SwiftUI à tout moment. • Cours : Les bases du développement d'applications • Défis : applique ce que tu apprends et gagne des XP • Aide-mémoire : référence rapide (types, struct, class, modificateurs, navigation) • Suivi : niveau, XP, streak, bilan de la semaine Idéal pour débuter en développement d'applications Une partie du contenu est gratuite ; l’abonnement Premium débloque tout et retire les publicités. Conditions d’utilisation (CLUF) : https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

COSS4 screens
Dev Mastery4 screens

Verdict

The call

The clearest difference is in-app purchases: COSS at none against Dev Mastery's 1. COSS also leads on ads (none vs shown) and device support (3 vs 1). Dev Mastery's advantage is update cadence (every 4 days vs every 6 weeks). On price 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. Dev Mastery sells 1 in-app purchase, starting at $8.99 per month. COSS asks for nothing beyond the download.

UpkeepUpdate frequency

COSS ships an update every 6 weeks, Dev Mastery every 4 days. The most recent releases landed on September 29, 2026 and September 26, 2026 respectively.

Scorecard5 real differences · 3 level
COSS versus Dev Mastery: the parameters behind the verdict, then further details
ParameterCOSSDev Mastery
PriceFreeFree
Positive reviews83.3% of reviews—
Update frequencyEvery 6 weeksEvery 4 days — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationFree—
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS14.0 — better17.0
Further details — not scored
Size40 MB10 MB
Age rating4+4+
Developer5FEEDBACKSofyan Zarouri

In-app purchases

None

COSS

No in-app purchases

1 purchases

Dev Mastery

Subscriptions1
  • Premium Mensuel$8.991 Month

Questions

Is COSS free?
COSS is free to download, with no in-app purchases.
Is Dev Mastery free?
Dev Mastery is free to download, with in-app purchases available.
Do COSS or Dev Mastery have ads?
Dev Mastery shows ads; COSS does not.
Which is updated more often, COSS or Dev Mastery?
COSS ships an update every 6 weeks, and Dev Mastery every 4 days. Most recently, COSS was updated on September 29, 2026 and Dev Mastery on September 26, 2026.

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