Numa

Sources and photo credits.

All in one place: where the numbers, facts and photos on this website come from.

Studies and support

  1. Sohn, S. Y., Rees, P., Wildridge, B., Kalk, N. J. & Carter, B. (2019). Prevalence of problematic smartphone usage and associated mental health outcomes amongst children and young people: a systematic review, meta-analysis and GRADE of the evidence. BMC Psychiatry. pmc.ncbi.nlm.nih.gov/articles/PMC6883663
  2. Castelo, N., Kushlev, K., Ward, A. F., Esterman, M. & Reiner, P. B. (2025). Blocking mobile internet on smartphones improves sustained attention, mental health, and subjective well-being. PNAS Nexus, 4(2), pgaf017. doi.org/10.1093/pnasnexus/pgaf017
  3. WHO Regional Office for Europe / HBSC (2024). A focus on adolescent social media use and gaming in Europe, central Asia and Canada. hbsc.org/?p=274696
  4. Külling-Knecht, C., Waller, G., Willemse, I. et al. (2024). Ergebnisbericht zur JAMES-Studie 2024. ZHAW Zurich University of Applied Sciences. zhaw.ch (PDF)
  5. Pro Juventute, counselling 147: 147.ch · Die Dargebotene Hand 143: 143.ch
  6. Find A Helpline, worldwide directory of helplines: findahelpline.com

Sources checked: 5 November 2026.

Comparison with other providers

  1. Apple Support, Screen Time: schedules and limits on iPhone: support.apple.com/guide/iphone/iphb0c7313c9
  2. Google, Android Help on Digital Wellbeing: support.google.com/android/answer/9346420
  3. Brick, FAQ: getbrick.com/pages/faq and shop: getbrick.com
  4. Brick on the App Store (US): apps.apple.com/us/app/brick-ditch-distractions/id6448794069
  5. Unpluq, product pages: unpluq.com/products/premium-subscription and unpluq.com/pages/family
  6. Unpluq, FAQ: unpluq.com/pages/faq
  7. Opal, pricing: opalapp.com/pricing and opalapp.com
  8. Opal on the App Store (US): apps.apple.com/us/app/opal-screen-time-for-focus/id1497465230
  9. Foqos on GitHub: github.com/awaseem/foqos

As of 5 November 2026.

Photos

  1. Joel & Jasmin Førestbird: Photo on Unsplash
  2. Luca Bravo: Photo on Unsplash
  3. Vitaly Gariev: Photo on Unsplash
  4. Omar Ramadan: Photo on Unsplash
  5. Priscilla Du Preez: Photo on Unsplash

All photos from Unsplash, free to use under the Unsplash License. Product photos, card image and app screenshots: Numa.