DE 
For most Android smartphones and tablets, no operating system or security updates are provided by the manufacturer for two to three years after market launch.
Such a device should not be used for security reasons.
As environmentally conscious planetary inhabitants and as a security measure against malware infestation, we should, however, continue to use these devices, as long as they are still in good shape on the hardware side, for as long as possible, if there is an alternative third-party firmware variant for our model at all, also known as "Custom ROM" or "Aftermarket Firmware".
Added value of a custom ROM or aftermarket firmware
Custom ROMs offer us - based on the free Android Open Source Project (AOSP) - a secure platform with regular operating system and security updates.
Most initiatives that provide custom ROMs for different devices free of charge deliver the Android operating system without any Google Apps (also referred to as "GApps" for short), but usually offer the option of installing the GApps to different extents during the installation process via the Linux command line. Thus it is possible to provide only the Google Play Store functionality, up to installing the full scope of all GApps, such as Google Maps, Gmail, Google Now, Google Drive or Google Play Music, ..... So if you choose to do without most GApps, you will be rewarded with improved battery life, as many of these apps otherwise consume power in the background.
To protect the resources of our planet and also to mitigate the human rights problem from mining to production of new devices, there is the possibility for many models to install such a custom ROM, e.g. "LineageOS" or "/e/OS", which are usually geared towards security and data protection and often in principle enable higher battery life, see https://de.wikipedia.org/wiki/Liste_von_Android-Custom-ROMs.
The GApps can mainly come from either of the following open source projects: MicroG, or Open GApps.
Android Aftermarket Firmware installation service
By installing a custom ROM, all data on the device is deleted. The smartphone is connected to a PC via USB and during the procedure, which is also called "flashing", I must first install an alternative boot loader via the Linux command line. Then the custom ROM can be flashed and, if desired, a variant of the GApps can be transferred to the device.
However, the whole procedure is not exactly trivial and difficult to implement by non-professionals.
If, for stated environmental, human rights and safety reasons, you wish to use your device as much as possible until the hardware fails, I offer a chargeable service that includes:
- Research whether there is even a reasonably usable custom ROM for the respective device: 21.00 € plus VAT
- Clarification whether and to what extent data should be migrated: (if yes: 42.00 € plus VAT.)
- Clarification of whether GApps are desired (and to what extent)
- Flashing the custom ROM, possibly the GApps and possibly migration of the data: 42.00 € plus VAT
In total, the service costs a maximum of € 105.00 plus VAT.
In principle, flashing a custom ROM is a rather delicate matter. In extremely rare cases, the smartphone or tablet can become completely unusable, it is then said to be "bricked", i.e. technologically worth as much as a brick. I therefore give no guarantee whatsoever for the success of the action - but the price for the service will then of course be refunded.
Interest aroused?
For customers in Oldenburg (Oldb) I offer this service as part of the Resource Center of ReparaturRat Oldenburg e. V.: https://ressourcenzentrum-oldenburg.de/shops/custom-rom/
