Electronics related android Apps on Google play:

1) ElectroBasics Calculator(Free):
Description:
A handy application for calculations related to basic electronic components
Includes:
1) Resistor Color Code(4,5,6 band) to value conversion and vice versa.
2) Capacitor 3 digit code to value and vice versa.
3) Calculator for calculating equivalent value of resistor or capacitor in series/parallel.

Best for Students, hobbyists and engineers..:)
Its a totally free app with no advertisement stuff.
If you like the App, kindly rate it.
link to app:-https://play.google.com/store/apps/details?id=com.Pangam_Gaurav.ElectroBasics_Calculator

2)The 8051 Simulator(Free):
Description:
Simulator for Atmel 8051 microcontroller.
Small application but does a large amount of work!!.

Simulating small assembly language programs in Computer is quite irritating and time consuming in the context of  the length of programs, this app gives you ease of programming at your finger tips quick and easy...

Features:-
 Auto suggestions for mnemonics:- As you start typing the programs line by line whenever you start typing a mnemonic the simulator loads a suggestion list matching to the initials.

Lets you view the memory locations at which the instruction is going to be stored in program memory so that you know where your code is going to be stored before execution.

ORG, EQU and END directives support

Since the simulator only works on hex values, you do not need to write 'h' every single time at end of data.

Run time features:-

Provides a detail view of SFRs, Ports, PC and time elapsed in nice and compact interface.

Also it allows modification of I/O Port values any time during execution.

Supports step by step execution with a option to reset the controller at any time during execution.

View data at any RAM location during run time by simply putting the address in the given space as shown in screen shots.

Extra feature:-
Writing a program getting a output, and then losing the program is worst part of a programmer's life..;)

This app knows this and so provides a option to save your work into a text document with neatly formatted lines.

This version is free and limited to only 5 lines of code.

3)The 8051 Simulator Pro (Paid):
Has no limits on no.of lines....