android mobile application(android studio)

I am searching for android developer(JAVA) , I will support extra details, it is not a big project. It is not hard for professional android developer, it is simple one. Code has to be implemented in android studio. Task → The app can be divided into three episodes: a) pressing Revert button opens next activity and displays provided text, but reverted; →→ moreover, during creating and destroying the second activity it should produce notifications with it's name, name of the proper events and current date; →→ also, the activity contains a button that finishes it; b) next, there should be a picture imported from outside of Android Studio (can be mine or custom); c) next is a set of three apps: →→ first (built in the main one) is a simple calculator, containing two text fields (number fields), a button and place for result and type of operation. Pressing the button will launch an application, chosen by user from the two described below, which calculates a result and displays it on the screen along with done operation's type. →→ second is an app without an interface, purpose of which is to receive an intent with data from the first app, display the arguments using toast, sum them up and return to the first app. →→ third app works similarly, but it subtracts values instead of summing. →→ launching second or third app independently should make it show a toast about no arguments to use, without displaying any interface. d) below there should be a chronometer that counts time from the start of the program; e) whole app should have customized appearance and colors according to theme used in the app and mode of the device (light/dark).