Personally, I'm a big believer in pencil and paper work. I think that,while devices are handy, they can keep kids from learning how to do the basics on their own.
It would be difficult to say more without knowing the subject your niece is taking which allows this use of devices. Math? The kids need to do this work on their own-- and to know how to do it on their own-- without a calculator. If they need to double-check their work,you work the answer backward through the problem. If it was a question of composition? It might be reasonable for the teacher to ensure that kids without devices might use the computers in the computer lab or media center (what we used to call the library) during that class time.
In regard to education equality-- that's a hard one for me. I could bemoan a situation like this in my son's school, where some kids families do have enough money for their kids to have a device to take to school. But there's a bigger picture out there, where kids are taking courses with 40 other kids, or not getting more than 15 mins of recess (daily) because the school's test scores are so low, or not getting 'specials' on a regular basis, like art and music. Some kids don't have a neighborhood school and have to bus more than a half-hour away. So, no, schools are NOT offering the same opportunities to everyone. That's an unfortunate reality of the world we live in, where the federal funding is hinged to test scores and many families have both parents working full time, so many latchkey kids don't get any help on their homework. (I was one of these kids, btw. It was extremely difficult when it came to subjects I was baffled on along with higher student numbers in the classroom.)
We are fortunate enough to live near a fairly affluent neighborhood; our school is one which does a lot of fundraising for our own school, and a good percentage of those funds go into the district 'pot', as it were. While our school is still tapping parents to donate funds (and items for an annual auction), I feel that we donate what we can and then have to let the chips fall where they may. (I should add that we are fortunate enough for me to be a SAHM and so I spend a lot of time volunteering at the school to offset what we can't donate financially. But for parents who have to show up for their jobs each day or they might lose pay or get fired-- I completely 'get' why they aren't able to do this. They have their own children to feed.) This is a problem parents alone cannot rectify. NCLB created a great opportunity for privatization of education and sucked the dollars out of the public school system. Because of this, some parents are taking on the responsibility of educating their children themselves, because what they have to offer their child is better than what the public sector can provide. Even with vouchers, not every child can afford to go to private schools nor can they all lottery into those schools. It's a sad state of affairs, technological inequality is one of the 'tip of the iceberg' indicators that something deeper needs to change.
ETA: something which I think bears mentioning-- It is incredibly important for us, as parents, NOT to give our kids something to moan about. Personally, if it were my kid needing some device for a class which was VITAL for him to succeed-- I would move heaven and earth to get it, even if it meant not taking a vacation or selling some of our other belongings or taking on babysitting for a while to save that money. We as parents have to teach our own kids not to focus on fair/unfair and, instead, to teach them how they CAN do things. There are work-arounds to most problems; they aren't easy or convenient and sometimes, they really go unrewarded. (For example, I wasn't able to go to college and had a lot of hindrances to this when I was younger, so when I decided to pursue early childhood ed, I read every book I could get my hands on, went to the workshops my county offered, shadowed teachers I admired-- I don't get a piece of paper which says I earned a degree for this work. It is for ME and my own edification.) We have to remember that when our kids don't 'have', it's important not to point out the disparity or complain about it, but to point them in the right direction so that they can achieve their goals. That is of far more value, in my opinion.