Is it possible to make some android/ios app (or web app) and make widget/button which enable/disable some firewall rule?
ROS supports API which allows to control (certain aspects of) device. So yes, it is possible to make android/iOS app which (by using API) can enable/disable firewal rule. ROS is extremely flexible.
Does an app, which can be directly used for that, already exist? Not that I know of. ROS, being extremely flexible, makes things a bit harder (every device can have pretty different setup and having single app, which would fit, is next to impossible).
what is ROS?
The fact you ask this question combined with your first post scares the hell out of me …
Adding to mkx’s response: the Android app can be used to enable/disable a firewall rule. Not one button switch so maybe not enough for you.
Don’t know about iPhone (I actively avoid anything related to that eco-sphere).
Question from my side: why would you want to do that (toggling firewall rule) ? What’s the requirement ?
I want to quickly turn off internet on my kid’s phone (enabling firewall rule). I already do it but I need to log in to the webiste (webfig) and then click on the small button. I was wondering if there is easier way to do it.
why not use Kid Control for this? There is built in function just like that. Disable internet for all of childs devices. Check KID CONTROL in the android app main menu
Kids use iPhones, and I use parental control. They have time-limited app usage, but this is not the perfect option for parents. Sometimes I need my kid to immediately stop watching the iPhone (like dinner time), but he still has not reached the daily time limit on the YouTube app, so I just go to the firewall and cut the internet off for this specified phone by enabling the firewall rule. But please do not focus on the way I deal with my kids. I would rather know a faster and easier way to enable or disable the firewall rule.
Kid control is EXACTLY for that. It works better than firewall, because it blocks at MAC comunication level. Please try before criticizing. It is a feature in all MikroTik routers. In the same app you use now for disabling your firewall, just different menu.
I said nothing about how you manage your childrens time. I suggested an existing feature in your router
And MAC addresses can not be changed on iPhone ?
My view:
Sounds like a game of “whack-a-mole” to me … kids will ALWAYS find ways to circumvent such roadblocks.
Here at home:
When it’s dinner time, phones away from the table on a dedicated spot.
Problem solved.
There are even people going out in a pub and the first thing they do, is they all put their phones on the center of the table.
So they can TALK to each other (interesting activity, no ?).
The first one to touch his/her phone, has to pay the bill.
You can easily change that to household chores.
No, MAC address can’t be changed on iPhone. Seems like nobody here has tried Kid Control feture. Please try and then report back 
I understood MAC randomization is default on iOS ?
And for the record: I toyed quite a bit with kid control when I still had a vacation house in France.
Works pretty well (but not on MAC level for the above mentioned reason): time restriction, volume restriction, bandwidth control, … works all very well.
I used IP address (and a long lease time corresponding to the rental period).
I thought you talk about kid control build in the phone. I didn’t know there is such an option KIC CONTROL in the mikrotik router.
This sould be under IP menu? I can’t find it, maybe my software is too old
IP:
ARP
Accounting
Addresses
Cloud
DHCP Client
DHCP Relay
DHCP Server
DNS
Firewall
Hotspot
IPsec
Neighbors
Packing
Pool
Routes
SMB
SNMP
Services
Settings
Socks
TFTP
Traffic Flow
UPnP
Web Proxy
I will learn about it later.
Please don’t understand me wrong. I just wanted to make it clear that I want to discuss about software way to solve my issue.
main menu
I just installed mikrotik app (before I used webfig) but I see this:
you have many years old router software, just like it says on the screen, choose option to upgrade first
Upgraded, now I see this option. I will test it. Thank you
BTW @Normis:
what’s version 7.10alpha48 about ? 
final proof that mikrotik indeed DOES TESTING before releasing 
And it took 48 tries to actually do some testing? 
bugs are being fixed between each alpha, they are not made just to increase version number