Kids 5 & 3 (but very very nearly 4). Youngest has some mobility issues.
have a tablet - 2-3
have a phone - when they start to need one for safety - so if they start walking to school after 10, then. Might be a bit earlier/later.
play date without you staying - with close friends with kids the same age, 2. School friends etc, 5ish.
go outside to play without supervision - in the garden with me pottering around in/out, in easy line of sight & hearing, 2ish. In the garden whilst I watch tv or something, maybe about 7, but it wouldn't happen as the younger one is usually around and needs additional supervision. Outside, Not until they are going places independently, but I'd be happy with them walking to a friends house thats round the corner etc at maybe 8/9.
cross the road - quiet side roads, maybe 7. Big roads 10ish. Though may need to tweak these for youngest due to the risk of her falling in the road.
have a sleepover - with close family friends 2/3. School friends, hasn't asked yet, it would depend on how well I know the parents etc. 6-8ish.
Fully bath/shower themselves - shower without me, maybe 7 if able, bath, a bit older.
go downstairs in the morning without you getting up - I'm happy for my 5yo to, but 3yo would want to come too, and can't manage stairs safely etc.
make their own breakfast - for cereal etc, whenever they are tall and strong enough to get the milk out, and not make a mess etc. Maybe 6.