A better way to include logos in the comments # (also inspired from here: https://stackoverflow.com/a/21997097/4143444)

app.R

library(shiny)
library(ttbbeer)
data("beermaterials")
library(tidyverse)
library(ggridges)
library(shinythemes)
library(wesanderson)
library(shinyLP)
library(scales)

# Define UI for application
ui <- navbarPage( 
####################
 title = tags$header("Historical U.S. Beer Materials",
        # this image should be in your www/ folder
        tags$img(src='beer-logo.png', 
                 # "left" makes the logo the farest edge
                 align = "right", 
                 style = "text-decoration:none;
                 border: 0;
                 margin: 0;
                 padding: 0px;
                 left: 0px;
                 # this helped center the image once it was re-sized
                 top: -16px;
                 position: relative;")),
 ####################                                  
                  theme = shinytheme("journal"), 
                  inverse = T, 
                  
                  tabPanel("Introduction", icon = icon("home"),
                           jumbotron(header = "Analyzing & Modeling Historical U.S. Beer Materials", content = "", button = F),
                           
                           fluidRow(
                             column(6, panel_div(class_type = "primary", panel_title = "How to use this app?",
                                                 content = "Explore the data visualzations to develop insights about the distribution of the ingredients used in beer production over time. Interpret the time series model to answer questions about predicting future beer materials usage.")),
                             column(6, panel_div("success", "Application Maintainers",
                                                 HTML("Email the: <a href='mailto:name@hi.com?Subject=Shiny%20Help' target='_top'>App Developer</a> with questions about bugs. or submit a issue")))
                           ),  # end of fluidRow
                           fluidRow(
                             column(6, panel_div("info", "App Status", "In-development during DataCamp course. Future versions will include updated data from the U.S. Treasury TTB portal as posted!")),
                             column(6, panel_div("danger", "Security and License", "Copyright 2017"))
                           )  # end of fluidRow
                           
                           
                           
                  ),
                  tabPanel("Exploratory Data Analysis", icon = icon("area-chart"),
                           tags$head(
                             tags$style(HTML("
                                             @import url('//fonts.googleapis.com/css?family=Indie+Flower|Cabin:400,700');
                                             
                                             h2 {
                                             font-family: 'Indie Flower', cursive;
                                             font-weight: 500;
                                             line-height: 1.3;
                                             color: #E8DE2A;
                                             }
                                             
                                             "))
                             ),
                           
                           
                           # Sidebar with a slider input for production year
                           sidebarLayout(
                             sidebarPanel(
                               sliderInput("year",
                                           "Production Year:",
                                           min = 2006,
                                           max = 2015,
                                           value = 2008, 
                                           animate = T, 
                                           step = 1, 
                                           sep = "")
                             ),
                             
                             # Show a plot of the generated distribution
                             mainPanel(
                               
                               fluidRow(
                                 column(6, 
                                        h2("Introduction to beer data"),
                                        p("The data displayed below is from the R package ", tags$a(href="https://github.com/jasdumas/ttbbeer", code("ttbbeer"))),
                                        p(HTML("<a href='https://cran.r-project.org/package=ttbbeer' class='btn btn-info' role='button'>See more</a>"))
                                        
                                 ), 
                                 
                                 column(6, 
                                        h2("Visualizing the data"), 
                                        p("Joyplots are partially overlapping line plots that create the impression of a mountain range."),
                                        p(HTML("<a href='https://cran.r-project.org/web/packages/ggridges/vignettes/introduction.html' class='btn btn-primary' role='button'>See more</a>"))
                                        
                                 )
                               ),
                               
                               wells(content = "Press the red triangular 'play' button on the year slider to loop through the years."),
                               plotOutput("distPlot")
                             )
                           )
                             ),  # end of tabPanel
                  tabPanel("Modeling", icon = icon("beer"))
                  
                             ) # end of ui

# Define server logic 
server <- function(input, output) {
  
  # data cleaning reactive
  bm_df <- reactive({
    # tidy the data
    names(beermaterials) <- c("month", "year", "malt", "corn", "rice", "barley", "wheat", "sugar", "hops_dry", "hops_extract", "other")
    beermaterials <- gather(beermaterials, key = material, value = pounds, -month, -year)
    # subset data by year
    bm_df <- beermaterials[beermaterials$year == input$year, ]
    
  })
  
  output$distPlot <- renderPlot({
    # plot joy plots
    ggplot(bm_df(), aes(x = pounds, y = material, fill = material)) + 
      geom_density_ridges() + 
      theme_ridges(grid = FALSE) +
      guides(fill=FALSE) +
      labs(title = paste0("U.S. Beer Materials in ", input$year), y="", x="pounds (log scale)") +
      scale_fill_manual(values = wes_palette("Zissou1", 9, type = "continuous")) +
      #scale_x_continuous(label=unit_format("K")) +
      scale_x_log10(label=unit_format("K"))
  })
}

# Run the application 
shinyApp(ui = ui, server = server)