After a two week on/off search I found my old RTL USB-DVB-T TV stick.
I added the USB-C to USB-A OTG adaptor and a short USB-A extension cable.
The demo versions Android SDR Touch and Aerial TV worked, so I bought the €4.19 (inc 78c VAT) licence in App for the TV. The full version is an upgrade by clicking the lock icon on the running demo app, no doubt to ensure you have the required USB stick as otherwise the app won't load.
Ireland uses DVB-T for HD, so the old USB stick works also for HD and SD H.264. UK would need a newer one for DVB-T2. A DVB-T2 USB stick will work on DVB-T.
Some (nearly all old ones from UK) DVB-T setboxes and TVs will not do H.264 decoding (UK HD only, which was only ever on DVB-T2). Ireland has always used only H.264 for DVB-T, even for SD as well, so many TVs, before DVB-T2 was standard, sold as Digital TVs in Ireland only worked on analogue (till 2012 switch off), or as monitors with DVD, Consoles or set-boxes. We did a survey in 2012 and every UK owned retailer locally and most of the Irish ones (due to UK domination on wholesale back then before Brexit) had no Digital TVs that actually worked as such in Ireland, yet the €8 DVB-T USB sticks worked on a laptop to PC because the H.264 decoding was done on Windows/Linux/Mac.
The USA uses a totally incompatible system for off Air (ATSC), see map
https://en.wikipedia.org/wiki/Digital_television so the common RTL USB sticks won't work. See map for your region Digital TV.
Regions where a DVB-T or DVB-T stick won't work
North America uses ATSC
South America and one part of Africa uses ISDB-T
Japan uses ISDB-T
China uses DTMB (Hong Kong may still use DVB-T)
Most do about 42MHz to 1.2GHz for SDR, but it's only 8 bit by bypassing the MPEG-2 TS decoder. So SDR and DTV use different Android drivers (free download).
Later when I get more Playstore credit I'll get full version of the SDR Touch app, which is about €8.99. It does various radio modes and needs an external upconverter for 50KHz to 50MHz (LW, MW/Broadcast and SW) which are available on Amazon, Ebay etc. It will do FM, AM, SSB etc on bandII, Air Band, 2m, 70cm, Marine etc. I've used it with free SW on Windows and Linux, including DAB and SSTV. DAB is now turned off here since the start of May 2021. Only RTE was prepared to use it and it had less than 50% coverage.
Better SDR based tuners are available. The dynamic range of 8 bits is terrible and really 12 bits is a minimum, but the SDR Touch app is worth while with a cheap DVB-T stick for casual FM-Radio, Marine (we have local coastguard weather), Airport (we are near Shannon) and Shanwick Air control as well as listening to Amateur radion on 2m and 70cm.
Some Android tablets and phones do not have the CPU and graphics performance needed. The Irish HDTV with optional subtitles was perfect on the TCL NxtPaper11.
Edit
According to reviews the SDR Touch key (€8.99 on Playstore inc Irish VAT) on Amazon can only be used on an Amazon Fire, not a regular Android device.