Parts from rockets like the Space Shuttle with working cargo bay doors, Apollo, Soyuz, Mercury, Gemini, and so fourth. Also space station parts, small, large, and extra large solar panels which are retractable, solar radiators, and working fairings with different payloads.

Android devices have an build in file browser and iOS can have that too with jailbreaking, so installing mods shouldn't be impossible.

Would be useful for lunar/interplanetary trips. The ability to see your periapsis in an encounter before arriving at the SOI, being able to see your trajectory around the sun while still in a planet's SOI (for making use of the oberth effect). This would also allow accurate slingshots.

A large box shaped part in which you can put your rover so when you land it opens up and the rover comes out.
make it so you can shut the cargo door and fly back with the rover.

An engine only in the Sandbox that never ran out of fuel. It would be EXTREMLY useful when completing large orbits.

So we can retract the legs and use them again!

So instead of making a ton of different struts just make a tool so you can resize the strut to fit your specific ship

Such as a construction base satellite. Once in orbit and activated, it will appear on the planets list. Giving you the ability to build and launch a ship straight from the satellite!

All of those random rockets floating around get very annoying and distracting. It would be nice if there was a way to select a rocket and delete it.

The probe capsule would require an electrical charge (from a battery/solar panels) to function but is lighter and smaller then it's manned counterpart

Make it so that we can have a different image for a different rocket engine by giving engine tags an optional element of flame.

I usually play on my Nexus 10, and I'd love to have the split screen option that was just added to the PC version

when you come encounter it you can click "automatically dock"

add subtitles on events like 'ready to launch' or 'we only have 10% of fuel..!' or 'parachute has been deployed' or 'trajectory is hyperbolic...' or 'refueling...' or 'detaching/detached!' or 'are you sure about this..?'

'you can even add 'houston we have a problem' when your rocket breaks off or on a collision course...

Allow autopilot to use RCS to match speed and velocity with your station, the catch is you have to be close enough to tap the ship in the normal view. Zooming out counts.

With the addition of RCS control, I find it difficult to place the thrusters such that the rocket's control is balanced. For example, translating left might also cause a slight rotation if the thrusters are not placed symmetrically about the center of mass. However there is currently no way to see where the center of mass is, other than trial and error.

title says it all, you should be able to toggle solar panels ans lander legs like RCS jets.

Examples: fuel used (fuel and RCS), fuel capacities at initial launch, time at initial launch (with year:day:hour:min:sec format), time in service, distance traveled, weight, number of landings, number of dockings, number of parachute deployments, number of landing gear deployments, number of wheel activations, amount of fuel refueled/defueled, maximum velocity, average velocity, body launched from, farthest distance from body launched from, number of detaches, maximum stress, maximum g-force, number of orbits achieved, distance traveled with wheels, distance traveled with parachutes deployed, total burn time (for each stage and each engine type), etc.