Skype is a voice/video calling app, as well as a messaging app owned by Microsoft. It has over 100,000,000 installs on Google Play.
Package name: com.skype.raider
Files of interest:
The /cache/skype-4228/DbTemp directory contained multiple files with no extension. One of these files (temp-5cu4tRPdDuQ3ckPQG7wQRFgU on our device) was actually a SQLite database that contained the SSID and MAC of wireless access points it had been connected to.
The SD card path will contain any images or files received in a chat. If a file is downloaded, it will be in the Downloads folder in ...