Sumdog vs Klock.io
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Sumdog
This app offers personalized math and spelling practice for children aged 5-14 through engaging games and adaptive learning. It uses diagnostic tests to tailor learning journeys and provides virtual rewards to motivate students. Parents can set up accounts for home use or connect to school-assigned work.
- Personalized adaptive learning
- Engaging single and multiplayer games
- Thousands of standards-aligned questions
- Virtual coin rewards system
- 3D avatar and house personalization
- Diagnostic assessment
Read full descriptionHide full description
Make learning fun with Sumdog! Sumdog delivers highly engaging personalized practice for math and spelling, both in-school and at home. Suitable for children aged 5-14, our adaptive learning games and online rewards motivate children to learn and encourages regular practice. When children first use Sumdog, we run a short diagnostic test to provide a snapshot of their learning and areas for development. Our adaptive learning engine then uses the outcomes of the diagnostic to ensure each child’s starting point on Sumdog is at the right level. From this point, our sophisticated adaptive algorithms create a personalized learning journey based for each child based on their progress. - Over 30 engaging single and multiplayer games - Thousands of standards-aligned questions designed to consolidate and extend in-class learning - Virtual coin rewards to motivate children to learn - A 3D avatar, house and garden for children to personalize “I never thought an online program could do so much in such short bursts of time.” D. Hendershot, West Elementary, Kansas, US. Account set-up If your child has an account from school: Your child can log in with their details from their school. They’ll then be able to access any work that has been set by their teachers. If your child does not have an account from school: In the Sumdog app, parents can purchase a family plan covering up to 3 children. Once you’ve done this, you’ll create logins for your child to use the app. This gives them access to Sumdog’s games, and thousands of math, spelling and grammar questions. Subscription details: Your subscription starts with a free trial period and then changes to a subscription from $8.99 per month. No commitment period. Download the app and get started today! The amount will be deducted automatically every month via your Apple account. As long as the "Automatic renewal" feature is not disabled via the Apple account settings on your device, the subscription will automatically renew every month no later than 24 hours before your subscription period expires. Sumdog Terms: https://learn.sumdog.com/en-us/about-us/terms-of-use Sumdog Privacy: https://learn.sumdog.com/en-us/about-us/privacy-policy
Klock.io
This app acts as a pacing tool for UK university admissions tests like ESAT and TMUA. It times each question individually, showing students if they are ahead or behind pace, helping them manage their time effectively during exams.
- Individual question timing
- Pacing status (ahead/behind)
- Per-question breakdown
- Customizable exam targets
- Syllabus point tagging
- Live Activity on Lock Screen
- Compact iPad timer window
Read full descriptionHide full description
Klock is a pacing tool for UK sixth-formers preparing for university admissions tests — currently the ESAT and TMUA, plus legacy ENGAA, NSAA and CAIE papers scored against the ESAT standard. These exams allocate a fixed number of seconds per question with no negative marking, so the dominant failure mode isn't lack of knowledge — it's spending too long on one question and never reaching the rest of the paper. Klock times a past paper the way the real exam is timed and shows the candidate, question by question, whether they are ahead of or behind the pace they need to finish. It targets UK Year 12–13 students applying to STEM courses at Oxford, Imperial and similar universities that require these admissions tests. WHAT IT TELLS YOU THAT A STOPWATCH CANNOT Every question is timed on its own, including the time you spend when you go back to one. Afterwards you get a per-question breakdown — on pace, slightly over, well over — so you can see which questions took the paper away from you, not just that it ran out. That is the difference between knowing you were four minutes short and knowing that question 14 cost you six. ONE TARGET, EVERY PAPER You tell Klock which exam you are preparing for once. Every paper you time is then graded against that target, whichever exam it came from — so ENGAA and NSAA past papers count as ESAT pacing evidence, and the numbers stay comparable. Extra-time entitlements scale the target proportionally. ESAT 27 questions in 40 minutes 1:28.9 per question TMUA 20 questions in 75 minutes 3:45.0 per question Practice with ENGAA, NSAA and CAIE Physics past papers, all with their official durations read off the papers' own cover pages. A paper that isn't in the list can be named and timed at its section's official format. TOPICS, NOT JUST TIMES Questions carry the syllabus points they test, taken verbatim from the official subject guides. Tag your own as you review — the spec code sits next to every label, because the code is what you look up in the guide — and the tags stay on the question, so a paper you come back to still says what each one was testing. ANSWER EVERYTHING Neither ESAT nor TMUA penalises a wrong answer, so a blank is a mark given away for nothing. Mark questions as answered while you work, and when the time left no longer covers putting something in every empty box, Klock says so in a way you cannot miss. ALSO • Live Activity on the Lock Screen and Dynamic Island, with a Next Question button you can reach without unlocking • A compact timer window that sits beside your PDF on iPad • Per-session CSV export — one row per question, with its lap time, target and pacing status • Nothing is lost to backgrounding, locking or a relaunch: every clock is derived from stored dates, never from a ticking counter PRIVACY No account. No server. No analytics. Ever. Everything stays on your device, and the privacy label says "Data Not Collected" because that is true. Klock is not affiliated with, endorsed by, or connected to UAT-UK, Cambridge Assessment Admissions Testing, or Cambridge Assessment International Education. ESAT, TMUA, ENGAA and NSAA are their respective owners' marks and are used here only to describe the papers this app helps you practise.
Screenshots
Verdict
The clearest difference is rating: Klock.io at 5.0 against Sumdog's 4.2. Klock.io also leads on in-app purchases (none vs 1). Sumdog's advantage is ratings volume (1.6K vs 1) and iOS requirement (15.0 vs 18.0). On price, update cadence, ads and device support 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
Both are free to download. Sumdog sells 1 in-app purchase, starting at $8.99 per month. Klock.io asks for nothing beyond the download.
Klock.io holds the better App Store score, 5.0 against 4.2. That said, the two scores are not equally well evidenced: Sumdog has 1.6K ratings behind it against 1, so its average is the more settled of the two.
Sumdog ships an update every 2 months, Klock.io daily. The most recent releases landed on October 17, 2026 and October 8, 2026 respectively.
| Parameter | Sumdog | Klock.io |
|---|---|---|
| Price | Free | Free |
| Rating | 4.2 (1.6K ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 63.7% of reviews | — |
| Number of ratings | 1.6K — better | 1 |
| Update frequency | Every 2 months | Daily — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 18.0 |
| Further details — not scored | ||
| Size | 134 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Sumdog Ltd. | Aaron Jabamani |
Customer experience
Sumdog
Klock.io
Bugs and requests
Sumdog
Reported bugs
4 issues- Flower Defenders game not working properly
- Goalz game not registering shots correctly
- Sudden logout issues
- Incompatibility with certain devices or browsers
Requested features
5 requests- Add more free games
- Bring back old 2D games
- Allow interaction with house and garden items
- Improve multiplayer functionality
- Add more customization options for avatar and house
Klock.io
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Sumdog
- Family Membership7 Days trial$8.991 Month
Klock.io
No in-app purchases









