5. Hatching Eggs Hatch your 2km & 5km eggs first. Always try to ensure that you have space for an egg in case the next one that comes along is a 10km egg. Delay as much as possible until your level is higher before you start hatching your 5km and 10km eggs. The 10km eggs gives awesome Pokemons but their level will depend on your trainer's level. Egg level is determined when you received it & not when you hatch it. TBC but eggs collected have the same level as the trainer during collection time up to a cap of level 20.

negisf is correct as is the faq. Note the strikethroughs.
I always hatch the 2km ones first then the 5km ones to ensure there's always at least one extra space. And forever hoping the next pokestop will give me a 10km egg.

Am using All G app from Play Store. Though it still use log in atleast it not overlay directly in PoGo app. It open with it own app.