It actually stands for TWL Installable Archive. They are nds apps you can install to the DSi home menu using a PCI'm thinking it probably stands for TWL Importable Archive.
But still what exactly are they
Ok, why thoTIA (TWL Installable Archive) is a fan-made DSi file type that contains DSiWare apps, similar to CIA.
The file type has been discontinued.
There's an easier way of installing DSiWare, where it's the "title" folder of the TWL NAND, but only contains data for the DSiWare title, and the "title" folder can be overwritten on the SDNAND root with it to install the DSiWare title.Ok, why tho
I can't use my home menu, my sd card is 4gb. I autoboot into dsimenu++I recommend you using Title Manager. It simplifies the intire progress for you. Just run it through an exploit, or through DSiMenu++, so you can later install Title Manager onto your home menu.
https://gbatemp.net/threads/release-dsi-title-manager-for-hiyacfw.518053/
That's also fine, but if you change your mind, create a partition and format the SD Card to 2GB.I can't use my home menu, my sd card is 4gb. I autoboot into dsimenu++