Rose quartz is supposed to be good against the negative effects of electronics. Some people claim any black stone is helpful.
There is one stone that is said to be particularly effective be it for electronics, negative thoughts or intent from others or on a spiritual level. This would be a Black Tourmaline. It shields against negativity of all sorts and may be carried in your pocket, work as a piece of jewelry, placed on or by electronics, put in the corners of the house or apartment, buried like a fence around the yard or placed in your car to deter aggression from others (it will not stop your stress or aggression if you get this while driving). In general, you may use it any way you can imagine and being that it shields instead of absorbing the negativity it does not need to be "cleansed" the way others do but it may be when you feel like doing it. For healing if carried or worn it pushes negativity back out of the body that you may have picked up or that had been directed at you.
You may consider a necklace or bracelet which can be cut and the individual stones placed where you want them to include carrying one in your pocket if that is how you want to use them. One thing that you may need to consider is that certain stones may have more than one use that can also make them inappropriate for certain people. In another answer Peridot is mentioned. Although it may be useful against certain negativity it is also said to have an effect of strengthening the immune system. This may not be a wise choice for anyone who either has or has a heightened risk of any dysfunction of the immune system such as MS, GBS, any CIP/CIDP or even some types of allergies. This is one of the peculiarities of Black Tourmaline, it does not pose a risk potential.
As for Citrine the orange variety would be the one to use to keep negativity away.
Hematite may give you a more positive outlook but for protection. It is a good stone to use for discharging negativity from other stones. You can place some in a bowl and place almost any of your other stones in it for a while such as overnight and then place the other stones in a bowl of clear Quartz to recharge them. The best way to cleanse Hematite is to place it with clear Quartz crystals. Water is harmful for Hematite due to its iron content.