For What's App: 

1. open WhatsApp
2. Go to Settings
3. Tap on Chats
4. Save to Camera Roll

 For the Telegram App:

1. Open the Telegram app.
2. Tap on the three horizontal lines in the upper left-hand corner of the window.
3. In the new menu, select Settings.
4. Scroll down to the Chat Settings section.
5. Slide the toggle next to Save to Gallery into the On position.

For Facebook Messenger:

1. Open Facebook Messenger
2. Click on the Settings gear icon
3. Scroll down in Settings
4. Click on “Save Photos to Camera Roll”
5. flip the switch to the ON position