Qubba Apps blog
Notes from building StudyOS and QScan: learning science, food scoring, and launching apps in 2026.
Why an AI tutor must cite its sources (and how grounding works)
A tutor that cites the page it learned from can be checked. Why language models guess, how grounding works, and what a real citation looks like.
FiLo, 7 min read
E numbers and food additives: what EFSA and the FDA actually say
What an E number means, how EFSA and the FDA approve and re-evaluate additives, and what the record shows on titanium dioxide, aspartame and Red No. 3.
FiLo, 10 min read
How food scanner apps calculate a score, and why it should be public
Food scanner apps blend a nutrient profile, an additive penalty and a processing class into one number. How the common formulas work and why they should be public.
FiLo, 8 min read
How to launch an app with a waitlist in 2026
A practical playbook for launching an app with a waitlist: the one promise page, TestFlight and Play testing limits, pre-orders, email rules and launch day.
FiLo, 7 min read
Spaced repetition explained: why self-scheduling flashcards work
Spaced repetition schedules each review just before you would forget. Here is the evidence behind it, how SM-2 and FSRS set the gaps, and how to use it for an exam.
FiLo, 8 min read