Facebook recently force their users to install Messenger app if they want to read/send messages from mobile devices. But here is a tip how you can do it other way around. Method to read messages from facebook that work in all devices – Android or iOS.
On Android :
Step 1 – Open in your browser – facebook.com and just press menu button while on any page. You will get menu like this (for Samsung phones this should be the left sensor button ) :

Read messages in facebook on mobile
Step 2 – Choose option “Request desktop site”. This will force browser to always show you the desktop version wich will show full options and allow you to read and send messages.
Thats is !
If you want for any reason to reset this option just follow the same steps and tap again “Request mobile site” to deselect it and go to mobile site.
On iOS
Step 1 – Open facebook.com in your browser, then tap on the address bar.
Step 2 – Scroll up to show hidden options and feautures
Step 3 – Select option “Request Desktop site”
Thats it ! From now on you can use the full facebook website options with no limitations. You can send messages and read them on your iOS device.
If you want for any reason to reset this option just follow the same steps and tap again “Request mobile site” to deselect it and go to mobile site.
If you like this tip on how to read your facebook messages with no Messanger installed please share.