Help me plan a week in London in April

I had a look at your profile and based on that and the fact you’re visiting London in April I’d suggest:

Head to Borough Market. It’s on Thursday to Saturday in the day time with around seventy stalls selling food produced in Britain. They’re really big on fresh coffee, bread, meats and cheese. Stop off at The Wheatsheaf for craft beer and proper British street food. The drunk mussels and pulled pork are both pretty tasty.

Take a RIB up the Thames River. Theses twelve-man inflatable boats are normally used by the Special Forces and shoot up the river at incredible speeds. It’s a unique way to see London.  

Go to Brick Lane, known as curry mile, and eat at Queen Of Sheba. Order the lamb shank or one of their specialist fish curries. If you go late, there’s a speakeasy at 202 Brick Lane called Danger of Death. Walk into the shop upstairs and take the unmarked door to the basement. It’s members only but if you’re decent to the bar staff they’ll let you in.

I see previous answers are pretty comprehensive, but for food try maybe the less touristy, less obvious areas known rather to locals. Go to Hoxton Square and find the Red Dog Saloon, arguably best burger in London, they also have fantastic meat. Also try the Meat Market in  Covent Garden Market, it's a little hidden, but worth the look.

Not sure what your interests are, but here are a few of my favorite places:

I would make sure to see the  Tower Of London. It's not a cheap attraction but it is beyond incredible, especially if you're into British history (which it sounds like you might be). There is so much to see and do that you could easily spend a whole day there. 

This is a little on the square side but I LOVE the The Household Cavalry Museum. The Cavalry is the organization that protects the Queen (they're the ones you see on horseback at every royal celebration) and this museum is very interesting if you're into that kind of stuff. 

I would also check out The Old Curiosity Shop. It's now a shockingly expensive shoe store but it was the actual shop mentioned in Dickens's novel. 

Ye Olde Cheshire Cheese is one of the best pubs in London and the oldest. That should be among your top three places to visit--and do not miss going downstairs! The food here is pretty good as well. My other favorite pub in London is the  Princess Louise. Adorable little Victorian pub that's recently been remodeled. 

This is a tad touristy, but I would try  Rules. The food is good (not fabulous), but the atmosphere is insane. There are all kinds of crazy English-themed murals and artwork and general English-y stuff on the walls and it's a lot of fun. 

There's always something interesting going on at  Kensington Palace and the staff they have working there is unbelievable--they're all walking textbooks of British history. 

Do NOT miss the  Regency Cafe for breakfast! Aside from serving fabulous food, the Regency looks like it hasn't been touched since the 1950s. Also, the guy who calls out the orders is such a character that I recorded his voice on my iPhone the last time I was there. You'll see what I mean. 

Ordinarily I wouldn't recommend this for someone with just four days, but if you love royalty, you might want to check out the  Museum of Brands, Packaging, and Advertising. They have a lot of royal memorabilia on display. 

This is wildly touristy, but I would not miss the famous   Harrods Food Halls. The food isn't cheap and it's not all that great, but wow, is it gorgeous. 

This suggestion is a little bizarre and not sure one I would make a priority, but you might enjoy the  Old Operating Theatre Museum & Herb Garrett just because it's so out of the ordinary and authentic. 

See  Saint Paul's Cathedral for sure but be sure to get a guide book on it or take a tour because there are all these funny little secret things hidden in the architecture and great stories behind them. 

Have a blast!!!

I will just mention one place to eat. St. John Bread & WineMenu is different everyday depending on what's available but everything was perfect! 

Enjoy.

Do an East London market tour! My favorites are  Brick Lane market, but be careful to go there on weekends as it gets crazy busy.

You may also want to check out  Columbia Road Flower Market which is beautiful on a Sunday. It also gets very packed but if you go during the week they have some really lovely boutique shops. It's especially festive during Christmas. 

On a Saturday  Broadway Market near  London Fields is gorgeous and has great food options and live music. It's brilliant for people watching. 

All of these markets are walkable from one another so you can do them all in one day. Enjoy! 

There is so much to do, see & eat in London.  Please tell me what time of year, what area of London you will be staying snd what are your interests.  

Go to Camden Town, you will love it!!

Hello. You can bought the London Pass that offers free entry to major museums, tours and attractions. You can combine the pass with a travel pass for the metro and bus service.