If your mobile phone has network issues or any issue in one part of it is not working, there are multiple other uses
Camera – Most mobile phones have awesome camera , can be used for photo, video and related applications
Camera + Gimbal - If your camera has good Video recording , you can Use for Video shooting. Purchase a Gimbal for video stabilization
Wifi Router – Can be used as Wifi Router to connect security cameras or can we used at home to connect laptops and other device
Front camera – If Front camera, Mic and Wifi is working it can be used for online classes
Alarm Clock
iPod or Music Player – if your mobile phone has multiple issue , you can use it as Music player if Audio is working
TV Remote - Amazon Fire TV stick, Roku, Apple TV come with remote but if you lose it, you can always download the app in your old phone and use it as TV Remote.
eBook Reader - Big Display screen mobile phones can be used as Ebook Reader. and also for memorizing Quran.
Calling – if you phone is slow only use it for calls and SMS – good for business giving to servants
Sell it - Even if some part of mobile phone is not working, it may still be worth spare parts - Sell it to mobile phone repair shops. Even if you dont get good price you know that it will be recycled or reused. You can ask us (Tech Point) to make you an offer
Security Camera.
If you have an old phone that's no longer in use, turn it into a home security camera. Download a security camera app like Alfred on your old and new device, then mount the old phone where you need it; just make sure the device has access to power. You can use something as simple as a suction cup mount for a car. Then use your current smartphone to log in and view the feed from your old smartphone.
You can also DONATE your old smartphone to Poor people or institutions that deals with old phones