What's new?
DSi/3DS theme, SD card, and first time users: If donor ROM is not set, a message will show, saying to please set Mario Kart DS as donor ROM. (thanks matt (from GBATemp) for the idea!)
Previews for iQue and black DS(i) boot screen are added to the settings screen. (thanks to
@Zmxhawrhbg)
The pseudo HDR logo screen now has a black background to blend in with the other loading screens. (by @Zmxhawrhbg)
Added Pong and Tic-Tac-Toe as bootstrap loading screen options. (Only works for unofficial bootstrap for now.)
Acekard 2i support has been removed, due to the Add Games menu showing contents of the SD card instead of the ak2i flashcard.
Bug fixes
Fixed bottom screen being off on DS(i) boot screen before ROM select. (by @Zmxhawrhbg)
Changing game location for non-NDS games gives no effect (stays on SD card).
Other minor fixes.

What's new?
Animated icons from DSi-Enhanced games (and a DS game translation of mine) now animate like they would on the DSi Menu on DSi, and 3DS HOME Menu on 3DS!
(For assumingly a few games, icon frames that don't use the first palette line will not be shown.)
For some ROM hacks and translations of DSi-Enhanced games, a fixed banner built into TWLoader will be used.
These apply to:
-Fire Emblem: Heroes of Light and Shadow (English Translation)
-Pokemon Blaze Black
-Pokemon Volt White
If you already have these icons before this TWLoader release, delete the icons at sd:/_nds/twloader/bnricons .
Welcome screen added for first-time users!
Only show selected game's box art in 3DS HOME theme.
Replaced DSi L/R button shoulders in 3DS HOME theme with 3DS button shoulders.
Fine print added below pseudo-HDR logo.
Donor ROM options removed for SDK5 games.
Bug fixes
akMenu/Wood theme: Long filenames no longer cause some text or icons to not show.
akMenu/Wood theme: Fixed game counter in 100s being out of bounds.
3DS theme: Fixed No cartridge text being out of text bubble.
Fixed bottom screen cutting to black during DS/DSi boot screen fade out, if appeared before ROM select.
Known bugs
DSi-Enhanced games added from flashcard via the Add Games menu, do not have their icons animated.

6.7.0

Now that DSiMenu++ has replaced TWLoader, this may only get updated if there's a specific bootstrap setting that either GUI needs to set.

What's new?

The TWLoader startup splash screen has been extended, with "Homebrew" now showing first.

Bug fix

If TWLoader says it's up-to-date on startup, it'll no longer wait for A button press.
Now sets correct console model for recent nds-bootstrap versions.

Known bugs

TWLoader will crash if quick-start isn't set. Hold both A and Y on the startup screen.

6.6.4

What's new?

If you have no cart or a 3DS cart in the card slot, trying to run an SDK5/TWLSDK game will bring up a message saying that the game may not work without a donor cart.
The troubleshooting message that appears after you launch a game, has been moved to the first-time welcome screen.

6.6.3

UPDATE 4/16/2018: nds-bootstrap v0.7.4 is now included!

What's new?

A troubleshooting screen is shown before rebooting into TWL_FIRM.
Extended banner sound (by joni)!

Improvements

Box art loading is now done in a separate thread, to cut down on menu slowdown.
Per-game settings are now saved, only if a setting is changed.

6.6.2

UPDATE 3/1/2018: nds-bootstrap v0.7.3 now included!

Bug fixes

Fixed bug where per-game setting for NES games aren't loaded, avoiding a TWLoader crash.
Fixed major bug where if a banner file doesn't exist, TWLoader will crash.

6.6.1

What's new?

Update features are back! You can now update TWLoader and nds-bootstrap again! (thanks to @thejsa)

6.6.0

UPDATE 2/24/2018: nds-bootstrap v0.7.2 now included!

What's new?

GitHub has dropped TLSv1/1.1 support as of 22 February 2018.
As a result, the update features have been disabled, so you are currently unable to update TWLoader or nds-bootstrap.
NES support added! NES games are ran via nesDS.
Place the ROMs at sd:/roms/nes.
Game limit per page has been increased from 20 to 40 (the limit in SRLoader)!
Animated icons with 8 palette lines are now shown correctly.
akMenu/Wood theme: You can now press SELECT to enable/disable akMenu/Wood icon scaling effect.
Useful if you don't want to be distracted while looking at the animated icons.
New GBC icon (by @Uupo03).
R4 theme: You can now press START to go to settings, instead of SELECT.

Bug fixes

The Add Games menu now caches DSi-Enhanced banners with the correct size.
Re-extract twloader.nds from the flashcardsdroot (all) folder, to the _nds folder of your flashcard's microSD card.
Also, please delete the banner files at sd:/_nds/twloader/bnricons/flashcard, then re-add your games to get the fixed banner files.
Fixed flashcard games not launching in R4 and akMenu/Wood themes.