I had brought Thingy:91 samples from nordic, however I am not lucky so far to get it working. iBasis SIM didn't work for me here in Germany, due to limited coverage.
Anyone is managed to run nRF9160 product with SIM from Vodafone or Telekcom in Germany?
Also, I don't want to develop on Thingy:91 by uploading the image every time. is there any extra software or hardware I need, so I can debug the application easily?
I also bought a Thingy91, thinking I could use it for development. But then I realised - if I'm serious, I'll need a debugger/programmer, such as a Segger J-Link, to connect to the Thingy's debug interface (which can also be used to program the nRF52840 on the Thingy91).
And then I realised that, really, what's needed for nRF9160 development is a proper dev kit (because I want to hook up my own sensors and measure current). So I bought an nRF9160-DK, which includes a built-in debugger. One nice thing is that that built-in debugger can, through a "Debug out" port on the DK, also be used to debug other boards, such as the Thingy91.
Or, if you have another dev kit that includes a J-Link compatible debugger, such as the nRF52840-DK, you should be able to use the debug out port on that to debug your Thingy91 (although I've not tested that). So if you already have another suitable dev kit, your only cost would be a SWD debug cable.