[Android] Free - RFS - Real Flight Simulator (was $0.99) - Google Play

This highly rated app is free. It has more than 93,000 reviews and the rating is 4.3 out of 5.
It does have IAPs but I think you can play the game just fine (and get a good idea of whether you like it enough to get the PRO version) without buying things. I mean, surely 93,000+ reviews cannot be that wrong. ;-)

From the website:

Live a unique experience flying in any part of the world and exploring sceneries and airports in high resolution with satellite maps, 3D buildings, runways, procedures and air traffic. Jump on board of real time flights, chat with other pilots and join them in multiplayer. Manage flight plans and interact with ATC controllers. Get access to thousands of community created liveries, customize all airplanes, their gauges, failures and weather conditions.
Become a real pilot!

Manual/Tutorial: wiki.realflightsimulator.org/wiki

FLY NOW:
-Takeoff, landing or full flight
-Automatic creation of flight plan

ADVANCED FLIGHT PLAN (PRO only)
-Multiple options to create/edit/duplicate complex flight plans
-Date/time: CUSTOM/REAL (with night and day cycle)
-Flight Plan with procedures for DEPARTURE, ARRIVAL, APPROACH and TRANSITION (SID and STAR)
-Aircraft: V-SPEEDS, GROSS WEIGHT LIMITS, FUEL BURN, FLIGHT TIME ESTIMATED with customization of FUEL, PASSENGERS and CARGO
-Weather/Metar Departure and Arrival: CUSTOM/REAL - WIND DIRECTION/SPEED, MAIN WEATHER (CLEAR, FOG, RAIN, STORM, SNOW), CLOUDS, CLOUDS BASE, TURBULENCE, GROUND TEMPERATURE

REAL TIME FLIGHTS (PRO only)
-40.000 real time flights every day
-Real time traffic for the 35 largest airports in the world and their connected destinations
-Jump on any available real time flight and bring it to destination

MULTIPLAYER (PRO only)
-Join hundreds of other pilots and fly together in any part of the world
-Chat with any multiplayer pilot

Features:

ADVANCED MULTI PANEL SYSTEM: personalize your instruments and gauges

AIRCRAFT: Custom liveries, 3D live cockpit, working parts and lights

AIRPORTS
35 HD: High res satellite imagery, lifelike 3D buildings, taxiways and departure, arrival and approach procedures, PBB and VDGS
500 SD: Runways, 3D buildings and departure and approach procedures
14000 LD (PRO only): Runways and departure and approach procedures
Ground and air traffic (PRO only)

ATC Air Traffic Control (PRO only)
-Interactive multi voice ATC procedures and communications
-Frequencies: ATIS, GROUND, TOWER, APPROACH, EN ROUTE, EMERGENCY

FAILURES: CUSTOM/RANDOM - ALTITUDE/SPEED SENSOR, FUEL TANK, LANDING GEAR, ENGINE, FLAPS, AILERONS, THRUST REVERSERS, TYRES, RUDDER, SPOILER, BRAKE, ELECTRICAL SYSTEMS, RADAR

SATELLITE TERRAIN (PRO only): High definition worldwide satellite terrains
SATELLITE HEIGHTMAPS (PRO only): High definition worldwide heightmaps
(Satellite data requires online connection to stream data)

LIVERIES: Create your airplane liveries and share them with other players around the world

IN GAME:
-ADVANCED MULTI PANEL SYSTEM:
.INSTRUMENTS: PFD, ND, FMS, Map, Engines, Fuel, Altimeter/Anemo
.INDICATORS: Air/Ground/Vertical Speed, Heading, Altitude AGL/ASM, ETE Next/Dest, Destination, Next WP, Nearest Airport, Ground/OAT Temp, Wind, Activity/Flight/UTC/Local/Arrival Time, Fuel, N1, V-Speeds and more
-ILS Instrument Landing System
-CONTROLS: Main Throttle, Flaps, Landing Gear, Spoiler, Brake, Rudder and Pushback
-GROUND SYSTEMS: GPU, PBB, PUSHBACK
-AIRCRAFT SYSTEMS: HUD, WP/AIRCRAFT/COMMS HUD, APU, ANTI ICE, NAV/BEACON/LANDING/STROBE LIGHTS
-ENGINES: Start/Stop Engines, Separated Throttles, ANTI FIRE
-FUEL: Weight balancing, fuel dumping and real fuel consumption
-AUTOPILOT: NAVIGATION, APPROACH (Automatic Landing System) + SPEED, HDG, ALT, V/S
-MASTER CAUTION ALARM
-VDGS: VISUAL DOCKING GUIDANCE SYSTEM on all HD airports
-MAP: air topography with airports and waypoints. Detailed airport view (HD Airport) + FMC and flight plan
-MULTI CAMERA

PAUSE/IN FLIGHT:
-QUICK ACTIVITY: Runway/Gate Takeoff, Landing, Short Landing, Next WP and Current Position
-DATE/TIME: CUSTOM/REAL
-AIRCRAFT: Full customization (Load/Passengers/Fuel) anytime during your flight
-WEATHER: CUSTOM/REAL
-FAILURES: CUSTOM/RANDOM/OFF

RESUME LAST ACTIVITY
LOGBOOK
ONLINE MANUAL/TUTORIAL

PRO Version requires a subscription

Enjoy!