Apple will be releasing iOS 8.4 at 8:00 am PT or 11:00 am ET in few hours along with Apple Music. Hence, it is the right time to save iOS 8.3 SHSH blobs. By saving SHSH blobs of iOS 8.3 you will be able to downgrade later when Apple stops signing iOS 8.3 firmware.
If you are on a jailbroken iOS 8.3 device it is advisable that you go ahead and save SHSH blobs by using TinyUmbrella so that you can downgrade later, if required.
The developer behind TinyUmbrella has updated TinyUmbrella to latest version which can save iOS 8.3 blobs.
The blobs are saved at:
Mac: ~/.tu/.shsh
Windows: C:Users~.tu.shsh
How to save SHSH blobs of iOS 8.3 Using TinyUmbrella
1. Download the latest version of TinyUmbrella beta . It is available for Windows and Mac both.
2. Download the latest version of Java from here.
3. Run TinyUmbrella and connect your iOS device to computer. TtinyUmbrella will automatically detect your device and download the SHSH blobs.
You have successfully saved SHSH blobs of iOS 8.3 devices iPhone, iPad, iPOd Touch using TinyUmbrella.