While using the Beepserv tweak on a jailbroken iPhone, it is recommended that you use a spare Apple ID.
Apple has been cracking down on [their own] users for using Beeper/Beeper Mini. It even caused Beeper to remove iMessage completely from their platform.
Using Beeper is still a tricky situation, please continue with caution.
Use a spare/throw-away Apple ID as it could get you, or your device, banned from using iMessage on any device.
This guide is also very experimental and hasn't been tested, but it's a great theory that may or may not work. So please continue with caution.
For full guides on specific iPhones and iOS jailbreaks, please check CFW - iOS Guide and continue with this guide.
Register your number with Beepserv:
Installing the tweak and registering your number
Jailbreak your iPhone and download the Beepserv-rewrite tweak
Depending on your jailbreak, you'll have to download the correct tweak; rootful or rootless
Make sure you have the following tweaks installed after you got jailbroken:
Ellekit (You will need to install this manually. This is needed to make Beepserv work)
Libhooker
Mobilesubstitute or Mobilesubstrate
After installing Ellekit, hit "Reboot" on your installer; Sileo or Zebra
Once the device is back on the homescreen, go to your Downloads and open the Beepser-Rewrite tweak in Sileo or Zebra and install it.
Once you have installed Beepserv-Rewrite, you will want to do a Userspace Reboot
This action may be different between jailbreaks.
If everything is done correctly, you should see the Registration Code in your Messages settings on your iPhone
Once you have your Registration Code, download the Beeper Mini (for iMessage) app on your Android device (The link is posted above with the requirements)
Open Beeper Mini and it should prompt you to enter your Registration Code
Once you entered your Registration Code, it will proceed to ask you to enter your Apple ID info
Please use your spare/throw-away Apple ID for safety of your Apple account
You should be able to use iMessage with Beeper Mini and start texting your friends or family!
Using BlueBubbles/AirMessage with your spare/throw-away Apple ID
Add your spare/throw-away Apple ID to your Mac
Set up iMessage for this Apple ID and accept the "new number" being added to your spare/throw-away Apple ID
Test it by sending iMessage texts to your number or to your friends or family
If successful, you should be able to use your BlueBubbles/AirMessage server to send iMessage texts on your Android or Web
Please don't delete Beeper Mini from your Android device, as it could mess up this process. You can disable notifications from Beeper Mini on your Android device.
Troubleshooting Options
Beepserv won't show a code or a new code
If Beepserv isn't showing a code or a new code, please try to re-jailbreak and do a Userspace Reboot again
I can't get my number registered
If you are seeing REG-REQ? texts showing on your Android device, but can't get your number registered with Beepserv, you are most likely being blocked by Apple or your carrier is blocking the service from happening.
What you can do is wait for a few days and try again, or contact Apple to try to lift the ban or flag off of your Apple account.
I can't send messages on Beeper Mini
If you're not able to send messages on Beeper Mini to make sure that everything is going smoothly, you may need to get a new Registration Code and try again.
My jailbreak keeps making my device reboot
I get it, this can be very irritating, especially if it's making the code change, making Beeper Mini not work anymore.
What you can do is look into meowbrek2 to do an auto-jailbreak, helping this problem in entirely.
Meowbrek2 doesn't work for all iPhones or iOSes, so please continue with caution.
Nothing is working still after the troubleshooting options
I get that this can be irritating, but don't worry yet. I recommend that you should uninstall Beeper Mini, get a new code and try it again.