Currently an extension is unable to add Service elements to the manifest so this isn’t possible without having to manually editing the manifest after the .apk is compiled.
Oh yes, but it still uses the microphones input. I wanted to use the audiooutput for the input…
Bonjour Ken,
J’utilise la norme NFC Rfid pour ouverture et fermeture de portes sécurisées par vigik. Le lecteur NFC d’app inventor n’étant pas complet je me suis détourné d’une fabrication d’APP. Vous serrez t’il possible de faire une extension qui lit l’ID unique du tag. Je n’ai besoin que de l’IDU mais je présume que d’autres auraient besoin de pouvoir modifier ce dernier.
Merci de votre travail qui nous arrange grandement.
Cordialement, Patrick
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What are the main issues?
@Ken @Patrick issue is, as far as I can tell, AI2 doesn't let you use NFC between phones and no body wants to talk about it. See here:
See the documentation:
http://ai2.appinventor.mit.edu/reference/components/sensors.html#NearField
For now this component supports the reading and writing of text tags only (if supported by the device)
It looks like Patrick is using a Vagik fob.
@TIMAI2 thank you for sharing. Unfortunately, can’t find working example of phone to phone NFC text tags.
@ken that’s cool and all, but most powerful use cases are NFC phone to phone. Able to do everything and more if this is possible you could with a fod. Can always pick up a cheap Android treat it like a fob. Apple didn’t just wake up a couple years ago and randomly decide to include NFC in all their devices going forward …
Article from 2013 on apples stance on NFC:
https://www.macobserver.com/tmo/article/heres-why-your-iPhone-will-never-have-nfc
Article from 2017 on apples stance on NFC:
https://www.rfidjournal.com/articles/view?16238
Wanted to point out the adoption from Apple since we well soon enough be able to compile our apps for Android and ios. Bluetooth and qr are useful in certain cases but programmable NFC where we can go phone to phone is scary useful. I would say extension is a good idea but it is so core to the future of AI2 that it should maybe be focused on by @ewpatton and his team. But if you make an extension we wouldn’t stop you 
You won't !
from Wikipedia:
Every active NFC device can work in one or more of three modes:
NFC card emulation
Enables NFC-enabled devices such as smartphones to act like smart cards, allowing users to perform transactions such as payment or ticketing.
NFC reader/writer
Enables NFC-enabled devices to read information stored on inexpensive NFC tags embedded in labels or smart posters.
NFC peer-to-peer
Enables two NFC-enabled devices to communicate with each other to exchange information in an ad hoc fashion.
As I understand it, the AI2 NFC component falls into the second category.
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@Ken @Taifun @TIMAI2 (and anyone else who knows how to do extensions) can we please work together on “NFC peer to peer” extension?
@mike I think collaboration and team-work is a great idea. However, I haven’t worked on NFC. Hopefully others will be able to team-up and work with you
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Hi @Hossein, thank you for your message back on this. Understood, and please stay safe and healthy. Thank you. - Mike
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An interesting application would be to improve the Listpicker by allowing you to insert an image and formatted text in each row.
There are already several extensions that do this, and MIT are working on these features built in to the listview.
For extensions:
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Thanks, I saw Andreas Costa’s extension. It seems interesting to me. If it works well …
Another interesting extension would be to be able to justify the text of a label
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Android doesn't have this functionality until Android OS 8.0+.
I think most people use a Webviewer in this situation.
What about a Comment Block extension accessible from the Built-in Blocks drawer or suitable area? May have to be under Extensions of course.
Importantly, when opened it opens to a decent size (eg bit smaller than Viewer window) by default but could be adjusted and with a decent size font that is not dependent on the current zoom factor. (As opposed to the current block comments which shrink to an unreadable size if zoomed out to view a larger area of blocks)
Provide both facilities to either stand alone or be attached to a code block as below.
Suggested options for placement in the Viewer window are:
1/ place in the viewer area like the Warning/Error/Backpack etc so that it is always accessible without scrolling and semi-transparent
2/ allow docking to the viewer window
3/ For a better form of Comment than current, let it “stick” to another block in a minimized form until opened.
Auto close when clicked away from etc
And of course multiple Comment Blocks able to be used.
Food for thought? Would provide a good means for documentation, ToDo lists etc
Would be left out of Build of course so needn’t add any overheads.
May exist of course, if so I will be pleased when someone lets me know. 
I am seeking an password extension having 4 numbers criated by user. It is possible? Tks