It´s been 3 years since I´ve visited Istanbul so I wonder is the akbil still the same as this one?

Yes. I still use the one from 10 years ago or something.

Thanks!

They are based on a product called iButton from Dallas Semiconductors. We use them in our designs occassionally too. Very useful devices.

These days, when you have left your akbil home, you usually pay the driver and he uses his akbil (don´t know if it is really his or the company´s) in your stead.

What is this device used for exactly? Is it useful to get one if we plan to visit Istanbul? What´s teh cost of getting one, how does it work?

Sorry for so many questions, just trying to understand, found the post interesting.

Many thanks in advance to anyone who will be kind enough to spare the time to explain.

in estonia we use them to get in the appartement building (home)...it´s like...an electronical key...

In Istanbul, we use a thingummabob like the one in the picture. You can load credits on this device using an automatic machine available at important stations.

By touching the metallic part of the device on the sensor of a turnstyle you make your payment and gain access. When you do this you hear a confirmatory beep sound if you have enough credit on your akbil. If not, you are warned by a different beep. Student akbils beep differently too. There is some discount for akbil users and other advantages such as a charge free transfer to train after a boat travel.

All means of public transportation (commuter train, ferries, passanger boats, seabuses, the subway system, trams, public buses, cable cars etc) work with akbil.

I just have to take it with me when coming to Istanbul and not - like it happened before - finding out in the plane: Oh, I forgot it.

Thank you Vineyards for this explanation.

so interesting...here in estonia this little thing has only 1 purpose - opening the door for getting back home...for all those busses libraries tickets to everywhere etc we use ID-card (it has this chip in the middle and through this chip it connects to internet and with pin 1 code you can sign in to everywhere and make all payments through internet banking on that card - for bus tickets theatre tickets etc, and with pin 2 code you can give your digital signature to any legal documents you need - without leaving home)...even for internet banking and making appointements to doc and voting on covernmental elections we use 1 plastic card...ID-card...really - so interesting...

...you said something about voting Yakamozzz...as i know in Turkey when people going to vote there will be painted on one finger nail something black....by this i think they avoid multiple vote isnt it ? Or this kind of fraud is still working in Turkey ? 

in estonia you either go to voting centre and get the voting papers for your signature or you sit back and relax at your pc, use your ID-card for voting and forget about it every personal ID-card has unique pin 2 code that is connected to your personal and unique id-code (some numbers that are just yours) and that way 1 person who has ID-card and a pin 2 code that is connected to only this 1 card, can vote as only 1 citizen...no fraud possible...yes, you can change your vote though, and in the end the vote that you gave the last right before this voting thing is closed up all over the country, is the one that counts as YOURS...under YOUR name...like i said - no fraud possible...at least so far you know that estonians are lazy people that´s why they do everything in internet even skype they invented because it´s cheap and lazy

WOW!!!!!!!!!!!! İ just looked up and really estonians invented skype ! İ learnt something new today 

in fact, i learned smth new and interesting, too

Also akbil means:

Akıllı Bilet = smart ticket

Akbils will be obsolete

Akbils used by millions of İstanbul people will become obsolete and instead magneic cards will beused. Transition from akbil to magnetic cards will be in stages. In the mean time it will be possible to use both akbils and magnetic cards. One will need to pay 10 TL for one time only to buy the magnetic cards and they will be topped up.

Source: here